1. Field of the Invention
The present invention relates to an image processing method and device, and more particularly, to an image processing method and device for determining whether an edge in an image is a block effect and filtering out the block effect.
2. Description of the Prior Art
In the technical field of image processing, MPEG (Moving Picture Experts Group) and/or JPEG (Joint Photographic Experts Group) compression is commonly utilized in applications that encode, decode, transmit, store, or play images. Typically, DCT (Discrete Cosine Transform) is performed on the images during compression, thereby causing some problems. For example, suppose an image is compressed utilizing unsatisfactory quantization coefficients. Thus, after the image is decoded, there may exist some discontinuity (generally called “block effect”) on block boundaries in the decode image due to that each DCT block (e.g. 8×8 block) in the image is separately encoded during compression without consideration for similarity between any adjacent blocks.
Conventionally, block effects in the image can be removed by the aid of related compression/decompression information generated during MPEG/JPEG compression. However, due to variety of image media presently used in the market, it is often hard to know the origin of the image, and it is also hard for a back end device processing the image to get the related compression/decompression information. Thus, how to effectively remove block effects from the image under such condition is still a considerable and unsolved issue.